Title - THERMOPLASTIC POLYMER BOTTLE, BLOW MOLD AND METHOD FOR ITS MANUFACTURE

Abstract

The object of the invention is to provide a bottle made of thermoplastic material such as PET, which provides an optimal compromise between mechanical properties and lightness, particularly due to its base. To this effect, the bottle according to the invention comprises a base (2), a body (3), and a neck (4). The base (2) comprises: a dome (9), a crown (12), an annular seat (13), a side wall (14), six main radial slits (16), five secondary radial slits (17) between the main slits (16), each having an end Ev in the dome (12) and a peripheral end Ep in the side wall (14). This bottom (2) is such that the ratio Mf / Vuf in which Mf is the mass of the bottom and Vuf the useful volume of the bottom (2), is less than or equal to 0.050 g / mL and such that the ratio  do / H do in which  do is the diameter of the dome (9) at its base (PB ) and H do its apex height (11) (PA ) along the Z axis or an axis parallel to Z, is greater than or equal to 4.4.The invention also relates to a method of manufacturing and a mold for the aforementioned bottle.

Description

BOTTLE WITH IMPROVED BOTTOM Scope of the invention

[0001] The invention relates to the field of thermoplastic material bottles such as polyethylene terephthalate or PET manufactured by blowing or stretch blowing a preform itself obtained by molding this thermoplastic material, for example by injection (ISBM technology: Injection Stretch Blow Molding).

[0002] These bottles are intended in particular to contain beverages, for example water or other beverages. The bottles of the invention may in particular be intended to contain non-carbonated beverages, for example still water.

[0003] The invention also relates to the blow mold used to obtain these bottles. Technological background of the invention

[0004] The manufacture of a PET bottle consists of blowing a preform obtained by molding PET, for example by injection or compression, consisting of a tube closed at one end and whose opening is defined by a neck intended to be that of the finished bottle. This preform is placed in a mold whose cavity corresponds to the body and base of the bottle. The preform is heated to a temperature above the glass transition temperature of PET. Pressurized air is blown inside the softened preform so that it expands and presses against the walls of the mold, perfectly conforming to the contours of the mold cavity. The blowing process can be completed by stretching using a sliding rod.

[0005] The rigidity and mechanical strength of the finished bottle are essentially determined by its shape, structure, thickness, and by the hardened PET in a more or less crystalline state. The bottle comprises, from top to bottom, along its vertical Z-axis when the bottle is upright on a flat support: a neck, a body, and a base. This body and base may be marked with various grooves / ribs / recesses, according to diverse and varied patterns, designed to give it an aesthetic shape and the required mechanical properties after filling, in particular impact resistance, sufficient rigidity, and satisfactory stability in an upright position. Plastic drinking water bottles are indeed stored in packs of several units wrapped in shrink-wrapped plastic film. For storage and transport, these packs are stacked, notably on pallets.It is therefore crucial that the filled bottles withstand the mechanical stresses imposed by such storage and handling solutions. 1681264 of 23 transport. Any deformation, denting, or damage to the filled bottles constitutes a defect that limits the sale and / or degrades the user experience.

[0006] The mechanical resistance properties of a plastic bottle filled with water, stored on pallets, by stacking several layers of packs of bottles wrapped under shrink plastic film, are determined in particular by the bottom of the bottle, and, more precisely by the hollow and raised patterns it has as well as by the mass of thermoplastic material which constitutes it.

[0007] Another factor taken into consideration by designers and manufacturers of plastic bottles intended to contain (still) drinking water relates to the amount of plastic material used. It is desirable, for both economic and environmental reasons, to reduce the amount of plastic material used, and therefore to seek to reduce the thickness of the various parts of the bottles.

[0008] Another factor taken into consideration by designers and manufacturers of plastic bottles intended to contain (still) drinking water relates to the manufacturing conditions. In particular, for obvious reasons of energy saving and therefore ultimately of environmental preservation, it is desirable to reduce the blowing pressure as much as possible, which is, for example, between 25 and 30 bar for 150 cl capacity bottles, for a standard injection blow molding technology, i.e. without vents around the injection point.

[0009] Patent application WO 2013 / 178905 describes a plastic container having a body and a base extending from the lower end of the body. The base comprises a peripheral seat defining a mounting surface, a concave arch extending from a central zone to the base, and a series of reinforcing assemblies extending radially from the central zone to at least the base. The arch has two concentric regions, namely a central region and a peripheral region, separated by an axial step extending annularly and continuously around the central zone, such that the central region is raised relative to the peripheral region. This step would serve as a means of stabilizing the container, particularly under extreme pressure and / or volume conditions. This plastic bottle with a specific base can be improved in terms of mechanical properties and weight reduction. Objectives of the invention

[0010] In this context, the invention aims to satisfy at least one of the objectives stated below. 1681264 of 23

[0011] An objective of the invention is to provide a bottle made of thermoplastic material such as PET, which provides an optimal compromise between mechanical properties and lightness, in particular thanks to its base.

[0012] Another objective of the invention is to provide a bottle made of thermoplastic material such as PET, whose mechanical properties evaluated in a palletizing test, in particular with regard to the ability of the bottles to stand upright, are notably improved compared to existing ones, while minimizing the mass of the bottle.

[0013] Another objective of the invention is to provide a thermoplastic material bottle such as PET, with an optimal compromise between mechanical properties and lightness, and suitable for blowing under usual conditions of preform heating and blowing pressure, for a standard injection blow technology (without vents around the injection point), or even at lower blowing pressures, for identical preform heating temperatures.

[0014] Another objective of the invention is to provide a bottle made of thermoplastic material such as PET, resistant to uncontrolled deformation, in particular to inversion or tumbling, especially when the internal pressure is high. Tumbling is a phenomenon whereby, when the container is placed on a flat surface, the axis of the container tilts relative to a vertical axis (due to the low weight of the container) and the container rotates around a theoretical vertical axis, straightening its axis, until it comes to rest on its own, when its axis aligns with the theoretical vertical axis.

[0015] Another objective of the invention is to provide a bottle made of thermoplastic material such as PET, which benefits from good stability when filled and stored on pallets.

[0016] Another objective of the invention is to provide a thermoplastic material bottle such as PET, which is economical, energy-efficient and as environmentally friendly as possible, particularly with regard to its manufacture.

[0017] Another objective of the invention is to provide an injection blow mold enabling the production of the bottle as referred to in the objectives above.

[0018] Another objective of the invention is to provide an efficient method for manufacturing a bottle by injection blow molding as referred to in the objectives above. 1681264 of 23 Brief description of the invention

[0019] The invention satisfies at least one of the above objectives and relates, according to a first aspect, to a thermoplastic polymer bottle, preferably made of polyethylene terephthalate or PET, obtained by injection blowing of an injected preform, comprising from bottom to top, along the vertical axis Z of the bottle resting upright on a horizontal support in a contact plane XY, a base, a body and a neck; the spatial reference frame of this bottle being an orthonormal frame [XYZ] with origin O; * the base comprising successively and in a centrifugal direction: - a dome with Z-axis extending inwards into the bottle and preferably showing a mark of the preform injection located in the region of the dome's apex, - a coronal arch extending towards the inside of the bottle, - an annular seat designed to be in contact with the support-plane in an XY contact plane on which the bottle can rest in an upright position, - a lateral wall extending in a non-horizontal direction, up to the body, has a height H of 15 mm with a height h0 located at the level of the seat plane, that is to say the plane which coincides with the contact plane XY of the support-plane on which the bottle can rest in an upright position, the junction between the lateral wall and the annular seat constituting an annular edge, - at least 3, preferably between 4 and 8, main grooves, preferably equiangular, extending radially from the dome to the lateral wall, defining between them, on the vault, portions of vault, - at least 3, preferably between 4 and 8, secondary grooves, preferably equiangular, arranged between the main grooves, preferably at angular equidistance from the main grooves, each extending radially between an end Ev in a portion of the vault (21) and a peripheral end Ep in the lateral wall; characterized in that - the ratio Pf / Vuf in which Pf is the weight of the bottom and Vuf the usable volume of the bottom, is less than or equal to 0.050 g / mL, preferably less than or equal to 0.045 g / mL, and, even more preferably, less than or equal to 0.035 g / mL; - the ratio d / D in which d is the radial distance between the Z axis and the end Ev of at least one of the secondary grooves and D the radial distance between the Z axis and the annular edge, 1681264 of 23 is greater than or equal to 0.65; preferably greater than or equal to 0.70; - the ratio 0do / Hdo in which 0do is the diameter of the dome at its base and Hdo is the height of the apex along the Z axis or an axis parallel to Z, is greater than or equal to 4.4, preferably 4.8.

[0020] These Pf / Vuf, d / D, and 0do / Hdos ratios are the result of a carefully designed arrangement of the shape and grooves of the bottle base, which leads to an optimal, mechanically speaking, distribution of the thermoplastic material in the bottle base. This arrangement also improves the flow of the molten plastic material in the mold during manufacturing. This leads to a particularly high performance of this bottle in a pallet test, described below, which consists of stacking several layers of shrink-wrapped, water-filled bottle packs on a pallet. The bottle according to the invention thus exhibits a level of quality corresponding to a low percentage of defects caused by the stresses of palletizing, compared to negative prior art controls.

[0021] The bottle according to the invention is further distinguished in that it possesses at least one of the characteristics stated below in paragraphs 22 to 44.

[0022] According to one feature, the thickness of the bottom of the bottle decreases radially constantly along a radial generating line G extending, outside the areas comprising the main and secondary grooves, from the Z axis to the annular edge.

[0023] This radial generatrix is ​​for example G2 along the cutting line (CC), shown in figure 7.

[0024] Preferably the thickness e is greater than or equal to 1200 μm at the dome level,

[0025] Preferably the thickness e is less than or equal to 150 μm at the level of the annular edge.

[0026] Preferably the thickness e is: - greater than or equal to 1200 pm at the dome level, and - less than or equal to 150 μm at the level of the annular edge.

[0027] Preferably, the bottle is such that the thickness of the base decreases radially at a constant rate along three generatrices G1, G2 and G3 extending from the center of the dome towards the periphery of the base, distributed equiangularly on portions of the vault 1681264 of 23 excluding any groove. Thicknesses are measured at different radial distances, increasing on each generatrix, from the center to the periphery. G1, G2 and G3 are thus defined as shown in figure 7 and by reference to the orthonormal coordinate system [XYZ] whose origin is point O: * G1: radial direction along the X axis, between the Z axis and the lateral wall of the bottom; * G2: radial direction at an angle of 120° relative to G1 in the clockwise direction of rotation, between the Z axis and the lateral wall of the bottom; * G3: radial direction at an angle of 240° relative to G1 in the clockwise direction of rotation, between the Z axis and the lateral wall of the bottom.

[0028] Thus, in one embodiment, for abscissas G(x) with respect to the Z-axis, with G corresponding to G1, G2 or G3, between 5 millimeters and the distance from the annular edge, for example from 5 mm to approximately 25 mm for a small volume bottle (for example less than or equal to 50 cL), or from 5 mm to approximately 35 mm for a large volume bottle (for example less than or equal to 150 cL), the thickness e of the bottom wall (2) can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; - for x = 30 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; - for x = 35 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm.

[0029] In a variant of this embodiment, for abscissas G(x) with respect to the Z-axis, with G corresponding to an average of the values ​​of e on G1, G2 and G3, between 5 millimeters and the distance from the annular edge, for example from 5 mm to about 25 mm for a small volume bottle (e.g. 50 cL), or from 5 mm to about 35 mm for a large volume bottle (e.g. 150 cL), the thickness e of the bottom wall (2) can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; 1681264 of 23 - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 pm; for x = 25 mm; 30 μm < e <150 for x = 30 mm; 30 μm < e <150 for x = 35 mm; 30 μm < e <150 μm, preferably 60 μm < e < 120 μm; μm, preferably 60 μm < e < 120 μm; μm, preferably 60 μm < e < 120 μm.

[0030] In another embodiment, for abscissas G(x) with respect to the Z-axis, with G corresponding to G1, G2 or G3, between 5 millimeters and the distance from the annular edge, for example from 5 mm to approximately 25 mm, the thickness e of the bottom wall (2) can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm.

[0031] In a variant of this embodiment, for abscissas G(x) with respect to the Z-axis, with G corresponding to an average of the values ​​of e on G1, G2 and G3, between 5 millimeters and the distance from the annular edge (15), for example from 5 mm to approximately 25 mm, the thickness e of the bottom wall (2) can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm.

[0032] Advantageously, the base according to the invention offers good axial distribution of the material. The standard deviation, at the same abscissa G(x) along the three generatrices, is reduced. The average standard deviation over the portion of the base extending from the Z-axis to the annular edge is thus, preferably, less than or equal to 35 pm.

[0033] According to another feature, the bottle is such that the ratio d / D in which d is the radial distance between the Z axis and the end Ev of at least one of the secondary grooves and D the radial distance between the Z axis and the annular edge, is greater than or equal to 0.65, preferably greater than or equal to 0.70. 1681264 of 23

[0034] According to another feature, at least one of the main grooves in the bottom of the bottle has a general shape of an inverted "U" in a straight cross-section, along a plane parallel to the Z axis; and the branches of the "U" form an angle alpha1 between 30 and 50°, preferably between 45 and 55°.

[0035] According to another feature, at least one of the secondary grooves in the bottom of the bottle has a general shape of an inverted "V" in right cross-section, along a plane parallel to the Z axis and the branches of the "V" form an angle alpha2 between 45 and 65°, preferably between 50 and 60°.

[0036] According to another feature, each portion of the vault of the coronal vault of the bottom of the bottle comprises a substantially straight radial profile.

[0037] According to another feature, each portion of the vault of the coronal vault of the bottom of the bottle includes a profile forming an angle alpha3 with the XY contact plane between 5 and 20°, preferably between 10 and 15°.

[0038] According to a preferred embodiment, that at least one of its parts, base, body and neck of the bottle, has a circular shape in right cross-section, along a plane parallel to the XY contact plane.

[0039] According to another embodiment, the neck of the bottle has a non-circular shape (for example oval or rectangular, in particular square) in straight cross-section, along a plane parallel to the XY contact plane.

[0040] According to another feature, the bottle has a volumetric capacity in centiliters: from 20 to 30 cL, or from 30 to 40 cL, or from 40 to 60 cL, or from 60 to 80 cL, or from 80 to 110 cL, or from 110 to 130 cL, or from 130 to 160 cL, or from 160 to 180 cL, or from 180 to 220 cL, or from 220 to 260 cL, preferably 25 cL, or 33 cL, or 50 cL, or 75 cL, or 100 cL, or 125 cL, or 150 cL, or 175 cL, or 200 cL.

[0041] According to another feature, each main groove has an end in the dome Ev and a peripheral end EP in the side wall. Furthermore, the end Ev of all or part of the main grooves is open and opens below the dome, and / or the end Ep of all or part of the main grooves is open and opens towards the outside of the bottle.

[0042] According to another feature, the end Ep of all or part of the secondary grooves is open and opens towards the outside of the bottle, preferably in front of the end Ep of at least one of the adjacent main grooves. 1681264 of 23

[0043] According to another feature, the end Ev of all or part of the secondary grooves is open and opens under the vault.

[0044] According to another feature, the end EV of all or part of the secondary grooves is profiled into a point, this point forming an angle alpha4 less than or equal to 30°, preferably 20°.

[0045] According to a second aspect, the invention relates to an injection blow mold, one part of which has an impression allowing the bottle according to the invention to be obtained.

[0046] According to a third aspect, the invention relates to a method of manufacturing the bottle according to the invention, consisting of implementing a preform, preferably obtained by injection, in a blow molding technology, possibly including stretching, using the mold according to the invention. Brief description of the drawings

[0047] This description is made with reference to the attached figures illustrating non-limiting examples of embodiment, and in which: Fig. 1

[0048] [Fig. 1] is a perspective view of a preform intended for the manufacture of the bottle according to the invention by blow molding. Fig. 2

[0049] [Fig. 2] is a cross-sectional view of Figure 1 along the median diametrical plane of the preform shown in this Figure 1. Fig. 3

[0050] [Fig. 3] is a front view of an embodiment of a bottle according to the invention. Fig. 4

[0051] [Fig. 4] is a perspective view of another embodiment of a bottle according to the invention. Fig. 5

[0052] [Fig. 5] is a bottom and front view of the bottom of the bottle in Figure 3. Fig. 6 1681264 of 23

[0053] [Fig. 6] is a perspective view from below of the bottom of the bottle in the figure 4. Fig. 7

[0054] [Fig. 7] is a bottom and front view of the bottom of the bottle in Figure 4. Fig. 8

[0055] [Fig. 8] is a side view of figure 7. Fig. 9

[0056] [Fig. 9] is a perspective view of the background of figures 7 and 8. Fig. 10

[0057] [Fig. 10] is a cross-sectional view along line AA of figure 7. Fig. 11

[0058] [Fig. 11] is a cross-sectional view along line BB of figure 7. Fig. 12

[0059] [Fig. 12] is a cross-sectional view along line CC of figure 7. Fig. 13

[0060] [Fig. 13] is a detail view H of figure 12. Fig. 14

[0061] [Fig. 14] is a cross-sectional view along line DD of figure 7. Fig. 15

[0062] [Fig. 15] is a cross-sectional view along line FF of figure 7. Fig. 16

[0063] [Fig. 16] is a diametrical cross-sectional view of the preform used to manufacture a bottle according to the invention used in Example 1. Fig. 17

[0064] [Fig. 17] is a side view of a bottle according to the invention used in Example 1 from the preform of Figure 16. Fig. 18

[0065] [Fig. 18] is a bottom view showing the bottom of the bottle shown in Figure 17. 1681264 of 23 Fig. 19

[0066] [Fig. 19] is a photograph from below showing the bottom of the bottle shown in figure 17. Fig. 20

[0067] [Fig. 20] is a partial perspective view from below showing the bottom of the bottle shown in Figure 17. Fig. 21

[0068] [Fig. 21] is a photograph from below showing the bottom of the negative control bottle used in comparative example 2. Fig. 22

[0069] [Fig. 22] is a partial diametrical cross-sectional lateral view of the preform used to manufacture a bottle according to the invention used in Example 3. Fig. 23

[0070] [Fig. 23] is a side view of a bottle according to the invention used in example 3 from the preform of figure 22. Fig. 24

[0071] [Fig. 24] is a bottom view showing the bottom of the bottle shown in Figure 23. Fig. 25

[0072] [Fig. 25] is a photograph from below showing the bottom of the bottle shown in figure 23. Fig. 26

[0073] [Fig. 26] is a partial perspective view from below showing the bottom of the bottle shown in Figure 23. Fig. 27

[0074] [Fig. 27] is a photograph from below showing the bottom of the negative control bottle used in comparative example 4.

[0075] The numerical references used in all figures designate the same elements. Definitions 1681264 of 23

[0076] In accordance with the terminology used in this text, the following non-limiting definitions are given by way of examples and illustrations for the interpretation of this text: - every singular denotes a plural and vice versa. - “thermoplastic” refers to a thermoplastic or moldable copolymer or homopolymer that becomes fluid, viscous, pliable, moldable above a specific temperature (e.g., the glass transition temperature) and returns to the solid / hardened state after cooling. Detailed description of the invention

[0077] The container at the heart of the invention is a bottle 1 made of thermoplastic polymer material, preferably polyethylene terephthalate or PET. Bottle 1, shown in Figures 3 and 4, is described below with reference to a three-dimensional orthonormal coordinate system [XYZ] with origin O. The Z-axis (ZZ) is the axis of bottle 1. The X-axis (X) and the Y-axis (YY) define the XY plane, which is the plane of contact between the bottom of the bottle and a horizontal support on which the bottle rests upright. The origin O of the XYZ orthonormal coordinate system lies in this XY plane. Figures 3, 5, 6, and 9, in particular, illustrate this XYZ spatial reference system.

[0078] The bottle 1 comprises, from bottom to top, along the Z axis, a base 2, a body 3 and a neck 4 delimiting the upper opening 5 of the bottle 1 and separated from the body 3 by a support collar 6, itself surmounted by a thread 7, intended to cooperate with a screw cap for closing the bottle 1. The body 3 of the bottle 1 comprises grooved and ribbed patterns, known in themselves and not referenced in the figures and intended to contribute to the mechanical strength of the body 3.

[0079] In the following description, the terms "inside", "internal", "outside", refer to an element close to or in the direction of the Z axis of the bottle 1 or within the enclosure 8 defined by the bottom 2, the body 3 and the neck 4, forming an envelope delimiting this enclosure 8 from the bottle 1, and the terms "outside", "external", "outside", refer to an element located in an opposite direction to the Z axis of the bottle 1 or outside the enclosure 8 of the bottle 1. The terms "bottom", "lower", "top", "upper" are understood with respect to the bottle 1 placed on a horizontal plane support XY in an upright position.

[0080] This bottle 1 is industrially produced by injection blow molding technology, from a preform heated sufficiently to be fluid, in a mold having the impression of the bottle. The blow molding is optionally supplemented by a 1681264 of 23 stretching using an axial rod introduced into the preform (“Injection Stretching Blow Molding” ISBM).

[0081] Figures 1 and 2 show an example of this preform 100, shaped like a tube with axis Z, defined by a wall 101, open at its upper end 102, which includes the neck 4 of the future bottle 1, and whose base 103 has a generally hemispherical shape. In the case where this preform is manufactured by injection molding, the lower end of the base 103 has, on the outer face of the wall 101, a protrusion 104 extending outwards along the Z axis. This protrusion marks the injection point of the preform 100. In a compression production variant, the preform does not exhibit such a mark.

[0082] As shown in Figures 5, 6, 7, 9, 10 and 11, the bottom 2 of this bottle 1 comprises successively and in a centrifugal manner: - a dome 9, - a coronary vault 12 extending towards the interior of bottle 1 (enclosure 8), - an annular seat 13 intended to be in contact with the support-plane in a contact plane XY on which the bottle 1 can rest in an upright position, - a side wall 14 extending in a non-horizontal direction (different from XY), up to the body, has a height H of 15 mm with a height h0 located at the level of the seat plane 13 which is coincident with the contact plane XY of the support-plane, on which the bottle 1 can rest in an upright position. As can be seen in particular in figures 10 & 11, the junction between the lateral wall 14 and the annular base 13 constitutes an annular edge 15 which forms a kind of demarcation line between these 2 parts of the bottom 2.

[0083] Figures 5, 6, 7 and 9 show that the lower face of the bottom 2 is marked by radial mechanical reinforcement grooves of 2 types: main grooves 16 and secondary grooves 17.

[0084] The base 2 is shown in Figures 5 to 14 as a cup virtually detached from the rest of the bottle 1. This virtual cup, taken in isolation, contributes to the definition of the bottle according to the invention. To this end, 3 generators G1, G2, G3 are defined as shown in Figure 7: G1: radial direction along the X axis, between the Z axis and the lateral wall of the bottom 2; G2: radial direction at an angle of 120° to G1 in the clockwise direction of rotation, between the Z axis and the lateral wall of the bottom 2, 1681264 of 23 G3: radial direction at an angle of 240° to G1 in the clockwise direction of rotation, between the Z axis and the side wall of bottom 2.

[0085] The bottom 2 can also be defined, in addition to its shape and height H=15 mm described above, by its mass Mf and by a usable volume Vuf. Mf is measured by weighing the dry bottom and Vuf by filling it with water up to a level such that the meniscus is concave, the edge of this meniscus being included in the plane perpendicular to Z corresponding to the upper end of the lateral wall 14 of the bottom 2.

[0086] According to the invention, outside the areas comprising the main grooves 16 and the secondary grooves 17, the thickness of the bottom 2 decreases radially constantly, from the Z axis (dome 9) at least to the annular edge 15, excluding the areas comprising the main and secondary grooves, i.e. for example along the control line 16 - shown in figure 7. Thus, in one embodiment, for abscissas G(x) with respect to the Z-axis, with G corresponding to G1, G2 or G3, between 5 and 35 millimeters, the thickness e of the bottom wall 2 can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; - for x = 30 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; - for x = 35 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm. In a variant of this embodiment, for abscissas G(x) with respect to the Z-axis, where G corresponds to an average of the values ​​of e on G1, G2 and G3, between 5 and 35 millimeters, the thickness e of the bottom wall 2 can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 pm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; 1681264 of 23 - for x = 30 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm; - for x = 35 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm. In another embodiment, for abscissas G(x) with respect to the Z-axis, where G corresponds to G1, G2 or G3, between 5 and 35 millimeters, the thickness e of the bottom wall 2 can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm. In a variant of this embodiment, for abscissas G(x) with respect to the Z-axis, where G corresponds to an average of the values ​​of e on G1, G2 and G3, between 5 and 35 millimeters, the thickness e of the bottom wall 2 can vary as follows: - for x = 5 mm; 1200 μm < e < 1600 μm, preferably 1300 μm < e < 1500 μm; - for x = 10 mm; 200 μm < e < 600 μm, preferably 300 μm < e < 500 μm; - for x = 15 mm; 100 μm < e < 300 μm, preferably 150 μm < e < 250 μm; - for x = 20 mm; 80 μm < e < 280 μm, preferably 100 μm < e < 220 μm; - for x = 25 mm; 30 μm < e < 150 μm, preferably 60 μm < e < 120 μm.

[0087] The dome 9 with axis Z extends inwards (enclosure 8) of the bottle 1. The region of the apex 11 of the dome 9 has a convex well 111 with axis Z. The mark 104 of the injection of the preform 100 corresponds to the well 111 seen on the outside of the bottom 2. The well 111 can correspond to an injection point of the preform. The apex 11 region is defined by the peripheral edge of well 111, in the PA plane perpendicular to Z. Alternatively, the apex 11 region of dome 9 is not well 111, but a point apex 11. The PA plane, orthogonal to Z, includes only the point apex 11. According to the invention, the dome 9 extends, preferably, between the plane PA and its base, which lies in a plane PB parallel to PA, comprising the circle corresponding to the inflection (i.e., a break in curvature) between the coronal vault 12 and the dome 9. The vault 1681264 of 23 coronal 12 in its entire thickness, is advantageously straight in cross-section view along the vertical plane including the Z axis. The distance between plane PA and plane PB corresponds to the height Hdodu dome 9 (figure 14). The diameter of the circle defining the base of dome 9 is designated by the reference 0do. The ratio 0do / Hdo is one of the remarkable features of the invention. Preferably greater than or equal to 4.5, it is, for example, between 4.6 and 10, or better still between 4.6 and 8.

[0088] The coronal arch (in the sense that it forms a crown between the dome and the base) 12 connects the base of the dome 9 to the annular rim 18 of the annular base 13. Like the dome 9, this coronal arch 10 is a thin section of the base 2, projecting centripetally towards the interior of the bottle 1 (enclosure 8). The thickness of this arch 12, for example, increases slightly from the dome 9 towards the annular base. Its inner face 12i in vertical section along the Z-axis (section CC of Figure 7 shown in Figure 13) is preferably straight, but according to one variant, it could be curvilinear or even wavy. In a preferred embodiment according to a rectilinear radial profile, this inner face 12i of the vault 12 forms an angle alpha3 with the contact plane XY, which can for example be on the order of 12°.

[0089] The annular seat 13, delimited by the annular rim 18 and the peripheral annular edge 15, is intended to be the contact area with the flat support on which the bottle 1 can rest in an upright position. It lies in the XY plane. Its thickness from the rim 18 to the edge 15 is advantageously decreasing, or even constant.

[0090] The annular edge 15 forms an inflection point from which the lateral wall 14 rises from h0 on the XY plane to a height of H equal to 15 mm at the plane perpendicular to Z corresponding to the upper end of this lateral wall 14 of the bottom 2. According to a notable feature of the invention, the thickness of this lateral wall 14 continues to decrease from the annular edge 15 to the upper end at H = 15 mm. In one embodiment, this thickness may be substantially constant.

[0091] The main grooves 16 are of a number of 5 in the embodiment of figure 5 in the embodiment of figures 6 to 14. These main grooves 16 extend radially from the dome 9 to the lateral wall 14. They are separated from each other by the same angular distance, of 72° for the embodiment of figure 5 and 60° for the embodiment of figures 6 to 14. 1681264 of 23 As can be seen more particularly in figures 5, 6, 7 and 9, the main radial ribs 16 each have an open central end 19 hollowed out in the dome 9 and an open peripheral end 20 located on the lateral wall 14. Figure 15 shows the general inverted "U" shape of the right cross-section of each main groove 16 and the angle alpha1 defined by the lateral faces of the groove 16, on either side of the median diametral plane PD (branches of the "U"). The angle alpha1 is, for example, equal to 40° plus or minus 5°. The main radial grooves 16 cross the entire coronal vault 12 and thus delimit similar portions of vault 21.

[0092] The secondary radial grooves 17 are arranged between the main radial grooves 16. In the example shown in the figures, the secondary radial grooves 17 are equiangular with respect to each other and are separated from each of the two related main radial grooves 16 by the same angle. There are 5 secondary radial grooves 17 in the embodiment shown in Figure 5 and 6 in the embodiment shown in Figures 6, 7, and 9. Each secondary radial groove 17 has an open end Ev located in a portion of vault 21 and a peripheral open end Ep imprinted in the side wall 14. As shown in Figure 7, each end Ev is separated from the Z-axis by a distance d, which is another of the notable parameters of the invention. Each secondary radial groove 17 can thus contribute to the stiffening and mechanical reinforcement of the bottom 2 of the bottle 1, without hindering the flow of the molten plastic material during injection blow molding. According to the invention, this distance d between Ev and Z is defined relative to the distance D, which is the radial distance between the Z-axis and the annular edge 15 (see Figure 7). Thus, the ratio d / D is advantageously greater than or equal to 0.65; preferably 0.65, for example between 0.70 and 1.0; and, even better, between 0.71 and 0.80. Figures 8, 10 and 11 show that the peripheral open ends Ev of the secondary radial grooves 17 are located at a lower height than the peripheral open ends 20 of the main radial grooves 16. Figure 15 shows the general "V" shape of the right cross-section of each secondary groove 17 and the angle alpha2 defined by the lateral faces of the groove 17, on either side of the median diametral plane PF (branches of the "V"). The angle alpha2 is, for example, equal to 55° plus or minus 5°. 1681264 of 23 According to a particular feature of the invention, each secondary radial groove 17 has a profiled shape whose tip is the end Ev, at a distance d from the Z axis. Advantageously, the angle alpha4 determined by this profiled shape is between 20 and 60, preferably between 30 and 20. This value is consistent with the search for optimal circulation of molten plastic material during the shaping of the bottle by injection blow molding, in order to obtain in the end a distribution of thermoplastic material adapted to the objectives of lightness and mechanical strength.

[0093] The embodiments shown in the figures correspond to a circular bottle shape in a straight cross-section, along a plane parallel to the XY contact plane. The invention also encompasses any non-circular bottle shape. Consequently, by convention, the qualifiers relating to the circular shape: "radial", "annular", "diameter"... would be transposed to the description of a bottle according to the invention with a non-circular shape in a straight cross-section. Examples

[0094] The following examples illustrate the performance of the bottles according to the invention in terms of mechanical properties / lightness compromise, as measured by a palletization test.

[0095] The bottles used in these examples are shown in the attached figures 16 to 27. Examples 1 and 2 (Comparative) - 150 cl bottles

[0096] 150 cL PET bottles are manufactured by injecting a preform model followed by blow molding. The blow molding is carried out by heating preforms using lamps distributed along the preforms, then introducing them into molds, then stretching and blowing them into the molds.

[0097] The molds consist of two half-molds for the body of the bottles and a mold bottom for the bottoms of the bottles.

[0098] The weight of PET in the bottom is adjusted by varying the heating intensity of the different lamps: an increase in heating at the bottom of the preform allows the amount of PET at the bottom of the bottle to decrease.

[0099] The bottles are analyzed by measurements (weight and volume of the base, distances, thickness measurements) and the bottles obtained are evaluated by a palletization test.

[0100] We also analyze and evaluate 150 cl bottles purchased commercially in France at the beginning of 2021, presented as being the lightest on the market in France. 1681264 of 23

[0101] The main characteristics of the bottles manufactured or purchased, as well as the results of analyses and tests, are reported in Table 1. Analyses

[0102] Weight and volume of the base: the base of a bottle is cut at a height of 15 mm. The weight is measured, as well as the usable volume.

[0103] Thickness profile: The thicknesses of the base are measured along three generatrices G1, G2, and G3 extending from the center of the dome to the periphery of the base, distributed equiangularly on portions of the vault excluding any grooves (see §

[0027] above). The thicknesses are measured at various radial distances, increasing along each generatrice, from the center to the periphery. For each radial distance, the average thickness for the three generatrices and the standard deviation of the thicknesses for the three generatrices are recorded. The thickness profiles are shown in Table 2.

[0104] All analyses are carried out on a sample of 3 bottles. The average values ​​are reported. Palletization test

[0105] The filled and capped bottles are grouped into packs of 6 bottles wrapped in shrink film. The packs are arranged on 800 mm x 1200 mm pallets, in 4 superimposed layers of 21 packs, separated by a layer of cardboard. The pallets of bottles are surrounded by plastic film.

[0106] The pallets are subjected to a transport simulation by placing them on a vibrating table for 4 hours, for storage for 10 days at 40°C at 40% humidity.

[0107] 216 bottles (43%) from each pallet were then examined by observation. The following results were reported: - Critical instability defects: number of bottles that do not stand upright (e.g., with an inverted bottom) - Critical verticality defects: number of bottles that lean when upright, with more than 8 mm of radial distance between the center of the cap and the center of the base. - Quality index: proportion of bottles with no defects or with minor defects on all of the following criteria: instability, sagging shoulder, deformed body (buckling), verticality, ovalization, lateral flattening of the body. 1681264 of 23

[0108] [Table 1] Example 1 Example 2 (comparative) Bottle Origin Manufactured Purchased Bottle Capacity 150 cL 150 cL Preform Figure 16 NA Preform and Bottle Weight 22 g 20 g Bottle and Base Figure 17 Base Details Figure 18 Figure 19 Base Weight 2.30 g 2.91 g Measured Base Volume 67 mL 66.5 mL Mf / Vuf 0.034 g / mL 0.044 g / mL d / D 0.72 0.64 0do / Hdo 6.9 2.55 Critical Instability Defects (number of bottles) 3 45 Critical Verticality Defects (number of bottles) 3 45 Quality Index (%) 41.7 21.9

[0109] It appears that the base according to the invention makes it possible, at a lower weight, to limit defects and increase quality after palletizing.

[0110] [Table 2] Example 1 Example 2 (Comparative) Bottle Origin Manufactured Purchased Bottle Capacity 150 cL 150 cL Distance from Center Average Thickness Standard Deviation Average Thickness Standard Deviation 5 mm 1419.00 100.434672 673.11 86.7193213 10 mm 457.44 72.6128924 497.33 72.9257933 15 mm 283.78 14.3982487 363.22 39.9279947 20 mm 215.11 8.25917828 439.44 47.1170946 25 mm 174.11 8.14817745 312.78 32.0689345 30 mm 137.56 7.00034502 214.44 12.4185974 35 mm 109.89 3.72537003 175.00 9.09806003 Average from 0 to 25 mm 509.89 40.7706338 457.18 55.7518277 Average from 0 to 35 mm 253.60 30.6541263 382.19 42.8965423 Comments The base offers and presents a regular distribution of material, well distributed around the perimeter of the bottle (low standard deviations) and with a profile that is only decreasing. The base offers and presents reduced thicknesses at the periphery, giving it an increased ability to regain its shape after stress.The base exhibits an uneven distribution of material, poorly distributed around the bottle's circumference (significant standard deviations) and with an irregular profile (20 mm excess thickness). The base also exhibits significant thickness at its periphery, resulting in a reduced capacity to regain its shape after stress. 1681264 of 23 Examples 3 and 4 (Comparative) - 50 cl bottles

[0111] 50 cl PET bottles are manufactured in a similar way.

[0112] The bottles are analyzed in a similar manner and the bottles obtained are evaluated by a palletization test of the same nature, adapted to the format of the bottles.

[0113] We also analyze and evaluate 50 cl bottles, purchased commercially in France in early 2021, presented as the lightest on the French market. The brand is the same for both the 150 cl and 50 cl bottles.

[0114] The main characteristics of the bottles manufactured or purchased, as well as the results of analyses and tests, are reported in Table 3. The thickness analyses are reported in Table 4.

[0115] [Table 3] Example 3 Example 4 (Comparative) Bottle Origin Manufactured Purchased Bottle Capacity 50 cL 50 cL Preform Figure 20 NA Preform and Bottle Weight 9 g 9.2 g Bottle and Base Figure 21 Base Details Figure 22 Figure 23 Base Weight 1.10 g 1.20 g Measured Base Volume 37 mL 39.5 mL Mf / Vuf 0.030 g / mL 0.030 g / mL d / D 0.75 0.76 0 do / Hdo 4.85 4 Critical Instability Defects (number of bottles) 0 42 Critical Verticality Defects (number of bottles) 9 15 Quality Index (%) 46.3 21.7

[0116] It appears that the base according to the invention makes it possible, at a lower weight, to limit defects and increase quality after palletizing. 1681264 of 23

[0117] [Table 4] Example 3 Example 4 (Comparative) Bottle Origin Manufactured Purchased Bottle Capacity 50 cL 50 cL Distance from Center Average Thickness Standard Deviation Average Thickness Standard Deviation 5 mm 1385.78 72.0472671 455.00 197.463993 10 mm 330.78 52.7609633 193.33 44.3148296 15 mm 171.44 11.8804609 153.00 15.123696 20 mm 110.33 4.48503793 153.00 15.3346189 25 mm 72.22 5.39532657 122.78 8.66658654 Average from 0 to 25 mm 414.11 29.3138112 215.42 56.1807449 Comments The base offers and exhibits a regular distribution of material, well distributed around the circumference of the bottle (low standard deviations) and with a profile that decreases only slightly. The base offers and exhibits reduced thicknesses at the periphery, giving it an increased ability to recover its shape after stress. The base offers and exhibits an irregular distribution of material, poorly distributed around the circumference of the bottle (significant standard deviations), and with a partially flat profile (same thicknesses at 15 and 20 mm).The base offers and presents significant thicknesses at the periphery, giving it a reduced capacity to regain its shape after stress.

Claims

1. A thermoplastic polymer bottle (1) obtained by blowing an injected preform (100), comprising from bottom to top, along the vertical Z axis of the bottle (1) standing upright on a horizontal flat support in an XY contact plane, a bottom (2), a body (3) and a neck (4); the spatial reference of this bottle (1) is an orthonormal [XYZ] system of origin O; * the bottom (2) comprising successively and in a centrifugal direction: - a Z-axis dome (9) extending into (8) the bottle (1), - a crown vault (12) extending into (8) the bottle (1), - an annular seat (13) intended to be in contact with a flat support in an XY contact plane on which the bottle (1) can stand upright, - a side wall (14) extending in a non-horizontal direction to the body (3) at a height H of mm with reference to a height h0 located at the level of the seat plane (13),the junction between the side wall (14) and the annular seat (13) that constitutes an annular rim (15), - at least 3 main slits (16) extending radially from the dome (9) to the side wall (14), which define between them, in the vault (12), main portions (21) of vault, - at least 3 secondary slits (17) arranged between the main slits (16), each extending radially between an end Ev in a portion of vault (21) and a peripheral end Ep in the side wall (14), characterized in that: - the ratio Mf / Vuf in which Mf is the mass of the bottom and Vuf the useful volume of the bottom (2), is less than or equal to 0.050 g / ml; - the ratio Ø do / H do in which Ø do is the diameter of the dome (9) at its base (PB ) and H do its apex height (11) (PA ) along the Z axis or an axis parallel to Z, is greater than or equal to 4.

4. 8 Claims follow,